Bad al tanks

[fgray1]

I need some help. I know there were some tanks that are banded. I had a friend of mine give me 3 aluminum tanks and I want to know if someone out there can identfy the markings for me.
1. DOT SP6576-2700 KAE E382

2. CTC DOT 3AL 3000 S80 M4002 B104446

3. CTC DOT 3AL 3300 S80 M4002 B31671

Would apperciate any help.
I don't want to waste time getting them hydroed if there no good and can't get them filled.

Fred

 

[LUBOLD8431]

First one is suspect. Look up that exemption code on DOT's website. I am not familiar with it...

The second two are Catalina cylinders, and they are fine...

 

[COVCI]

the first cylinder on your list was manufactured by Kaiser Aluminum under a DOT exemption number 6576 that expired in 1979 and was not renewed. Therefore, it is illegal in the US to hydrostatically retest this cylinder and place it back in service.

I am always looking for cylinders to use as examples in PSI-Professional Scuba Inspector courses I teach and this particular cylinder would be one I would give you a few bucks for and pay shipping in CONUS.

If you are interested, send me an email at covci@covci.com.

The other cylinders are manufactured by Catalina using 6061 alloy and fine cylinders assuming that it is current on hydrostatic retest and visual inspection performed by a trained inspector.

Hope this helps.

Chris
COVCI

 

[naturalsummer]

Copied this post from another board ... thanks for the info Daniel ... everyone should be aware so I am passing it on ...


Here is "The List" of scuba tanks that the DOT says are most likely made
from the :
· All DOT-3AL tanks manufactured under one of the following
exemptions or special permits: 6498, 7042, 8107, 8364, 8422
· All composite cylinders manufactured under one of the following
exemptions: 7235, 8023, 8115
· All Walter Kidde DOT-3AL scuba tanks.
· All Cliff Impact DOT-3AL scuba tanks made before July 1990.
· All Luxfer 80.8 cu. ft. scuba tanks (S80.8) made before May 1987.
· All Luxfer 72 and 100 cu. ft. scuba tanks (S72, S100) made before
August 1987.
· All Luxfer 80 cu. ft. scuba tanks (S80) made before January 1988.
· All Luxfer 50 and 92 cu. ft. scuba tanks (S50, S92) made before
April 1988.
· All Luxfer 30 and 63 cu. ft scuba tanks (S30, S63) made before May
1988.
· All Luxfer 40 cu. ft. scuba tanks (S40) made before June 1988.
· All other scuba tanks made in the US before February 1990 (except
Catalina).
· All scuba tanks not made in the US.
Unless proven otherwise, all scuba tanks in the above list should be
assumed as being made using the 6351-T6 alloy.

Note that many other types of cylinders (SCBA, Medical, Industrial, CO2,
etc.) were also made from the 6351-T6 alloy. However, for brevity, only
SCUBA type cylinders are listed above. See the DOT Safety Alert Bulletin
for information on those.

Also, it should be noted that Catalina cylinders were NEVER made from the
6351-T6 alloy. They were made using alloy 6061-T6, which as of yet, has not
been known to fail explosively. All of the manufacturers in the above list,
except Walter Kidde, switched to the 6061-T6 alloy on the dates shown.

The DOT has not as of yet issued a recall of these tanks - only a safety
alert. Essentially, if you own or use a scuba tank in the above list , you
should consider it as being a time bomb waiting to explode. You should
consider the tank unsafe until you learn for certain that it is made from
the new alloy. Sure, not many have exploded but the ones that have
exploded have done some serious damage.

 

[Genesis]

The 6576 cylinder is illegal to hydro and should not be used.

The others are fine, provided they're current on Hydro and Vis. 6061 cylinders (of which all Catalina's are) do NOT need a VIS+, and any shop that tries to tell you otherwise should be one you don't let touch your tanks.

The problem with the VIS+, while a very good test for neck cracking in the thread area (which is how a lot of the older 6351 tanks have gone "boom"), is that it is EXTREMELY sensitive to any contamination in the threads, and will register a "false positive" if there is ANY contamination there.

That will cause the shop to reject your tank, and depending on what you agreed to when you had them do the inspection, they might even condemn it or refuse to return it to you! Bad Karma there dude.

Since the 6061 cylinders have never demonstrated any propensity to fail the way the 6351s have, there is no reason to use a VIS+ on them and risk a false positive - or have an unscrupulous shop rob you of a perfectly good tank.

My personal policy with my own home compressor is that I will not fill any 6351 tank nor any with a "withdrawn" exemption. I also won't fill any steel tank that I have not personally seen the inside of and know where its been, as the real risk with steels is internal, invisible (without pulling the valve) corrosion.

I can do that because I'm just a guy with my own compressor and don't sell air. So if one of my friends wants a freebie, I can set the rules.

Its tougher if you have a shop and SELL air, although there are a lot of shops in Florida that won't fill 6351 tanks irrespective of their inspection status, and the number of growing. At least one shop in this area has said they will start refusing to do so as of Jan 1st of this coming year.

I'd send that bad one to Covci

 

[fgray1]

You were a great help.
As usual.
covci I e-mailed you.
Fred